HP Kayak XU Technical Reference Manual page 47

NOTE
CAUTION:
without the FastRAID option. For certain applications, read caching (i.e.
pre-emptive reading and caching of sequential sectors of data, to have ready
to use if needed) can accelerate operations.
Read/write caching is an advantageous option, but the primary function of
the FastRAID solution is to provide enhanced hard drive performance
through two supported modes:
• Raid0 (default configuration): This configuration provides data read/write
acceleration using one or two hard drives (of the same capacity and
speed) through disk striping. In general terms, data blocks are divided and
stored between two hard drives using a method called disk striping. It is
important to point out that there is no redundancy of data storage, and
the RAID 0 mode does not, in any way, reduce the necessity of backing up
stored data.
To obtain the benefits of read/write caching using the ARO-1130 adapter in a
system with only one hard drive, it is necessary to select the RAID0 mode.
• Raid1 configuration: This configuration provides software mirroring and
caching. Data is mirrored (duplicated) using a hard disk pair. If one disk
fails, the data is still available on the mirrored drive. The RAID 1
configuration also provides an improvement in performance using the
cache on the ARO-1130 adapter. It does not, however, provide the same
throughput as the RAID 0 configuration. In addition, because data is
mirrored, the storage capacity of your drives is only half of the physical
capacity of the drives.
One of the above modes may be selected using the ArrayConfig utility. This
utility is described in detail in the User's Guide supplied with the PC
Workstation.
The ARO-1130 adapter and hard drive(s) come preconfigured for maximum
performance (RAID 0) but may also be configured to provide protection
against data loss (RAID 1).
Configurations RAID5 and RAID10 are not supported.
The ARO-1130 adapter is supplied with 16 MB SIMM installed in the adapter
memory slot. If the adapter must be replaced, do not remove the SIMM
because the replacement adapter will be supplied with its own SIMM. In
addition, no re-configuration of the FastRAID I/O subsystem is necessary
following the replacement of the ARO-1130 adapter, as all information
concerning the FastRAID configuration is stored on the hard disk drive(s).
3 Interface Boards and Mass-Storage Drives
HP FastRAID Solution
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